Trunk links becoming error disabled

[k.a.clarke]

Hi

We are having intermittent problems where trunk links error-disable due to ETHCNTR-3-LOOP_BACK_DETECTED: Loop-back detected error.

So far it has happened on 2950 (12.1(22)EA9) and 2960 (12.2(25)SEE2) switches, with the latter only having one trunk link to the next switch.

We may be running into bug: CSCea46385, with the workaround of removing keepalives from the interfaces. If we do this, how will it affect spanning tree?

Thanks in advance.

[didyap]

I think this problem usually occurs when the keepalive packet is looped back to the port that sent the keepalive. One workaround for the problem will be to disable the keepalives on the affected interfaces and if you have not tweaked the spanning tree you may not notice any major performance issues. If you notice some performance issue the only other possible workaround will be to upgrade the IOS.